WASHINGTON --- Sen. Chuck Grassley has asked the Food and Drug Administration to respond to accounts that an agency-convened drug safety oversight board voted earlier this month to keep Avandia on the market by a one-vote margin amid agency considerations of a second warning for the drug label about heart attack risks.

Grassley said sources indicate the board vote occurred on October 2, so he’s also asking the FDA about the terms and conditions governing public notification with this sort of information.

The FDA first issued a heightened warning about Avandia and heart failure risk in August, following a May study that appeared in the New England Journal of Medicine regarding the drug’s cardiovascular risks.

“The Avandia case continues to present new rounds of questions about the way the FDA monitors and assesses drug risks and decides whether to let the public know about emerging risks,” Grassley said.